Clutch mechanism



Aug, 3l, 1937. R, P. I Ewls,

CLUTCH MECHANISM 2 Sheets-Sheet l Filed Oct. l0, 1932 Aug. 31, 1937. R R LEWIS 2,091,409

I CLUTCH MECHANISM Filed OCC. l0, 1932 2 Sheets-Sheet 2 y Patented Aug. 31, 1937 UNITEb ,STATES PATENT OFFICE Application october 1o, 1932, serial No. 637,124

9 Claims.

The present invention relates to clutch mechanisms, and more particularly to clutch mechanisms especially adapted for use in automotive vehicles.

Clutch mechanisms in common use today for automotive and similar purposes are of, generally, such construction that the pressure applied to the driving plates is not evenly distributed with the resultthat Vundernormal clutch operating conditions the facing material Wears away unevenly, and localized areas of the plates become excessively hot, causing comparatively rapid disintegration of the facing material and warpage of the metallicplates. While some clutch mechanisms in use today apply a fairly uniform driving pressure to the plate when the clutch mechanism is new, and the driving and driven shafts are in perfect alignment, after the clutch mechanism has been used for a short time, or in theevent that the driving and driven shafts are not assembled insubstantially perfect alignment, the drivingpressure becomes poorly distributed, with resultant excessive non-uniform weanand localized heating of lthe clutch element. 5 A further inherent disadvantage of prior clutch mechanisms resides in the fact that initial adjustment of the clutch at the factory is diicult and subsequent adjustment to Acompensate for wear of the clutch plates and for the purpose of establishing substantial parallelism thereof is almost impossible. Obviously non-parallelism of the clutch' plates, which are designed for slipping engagement with each other,.results in rapid Wear of the clutch elements, and causes clutch engagement to occur with a chattering and grabbing action.

Another Adifliculty. with. automotive clutch mechanisms in common use is that under highspeed, high-torque conditions, regardless of whether the clutch is correctly adjusted 4or not, slippage of the clutch plates occurs, causing rapid wear of the facing material and the clutch plates. In an eort to overcome this difficulty, driving pressures have been increased and while this ex- 45 pedient overcomes the difculty of clutch plate slippage under high speed, high torque conditions, it increases the pedal pressures necessary to operate. the clutch mechanism which is undesirable, particularly in vehicles of the pleasure car 50 class.

Accordingly, a primary object of the `present invention is the provision of a low cost clutch' mechanism wherein the driving pressure of the spring means employed is uniformly distributed 55 about the entire area of engagement of the clutch plates, so that uniform engagement, wear and long life are assured.

A further object of the present invention is to, provide a low cost clutch mechanism adapted for large volume production wherein driving' pressure is uniformly distributed about the entire area of engagement of the clutch members andthe elements are so related that proper distribution of pressure is maintained regardless vof substantial misalignment of the driving and driven shafts and clutch parts. f

A further'object of the present invention is to provide a clutch mechanism wherein adjustment of the clutch members may be readily established at the factory and after the clutch has been in use, should the necessity for so doing arise.

Another object of my invention is -to provide a clutch mechanism wherein novel means are ern-` ployed for exerting pressure on the driving plates. Other objects of the present inventionwill become apparent as the description thereof proceeds in connection with the accompanying drawings.

In the drawings:

Figure 1 is a longitudinal sectional view of the clutch mechanism forming a part of the present invention.

Figure 2 is a view of the clutch mechanism disclosed in Figure 1 as it appears when viewed from the right hand side of that gure, and partially in section, with the clutch housing removed for the.' purpose of facilitating Ithe illustration.

Figure 3 is a side View of the driven member, as it appears when removed from the clutch mechanism and having parts thereof broken away.

Figure 4 is a fragmental sectionvtaken on line 4-4 of Figure 1, looking in the direction of the arrows.` I

Figure 5 is a detailed sectional view taken on line 5-5 of Figure 2 and illustrates the associ--` ation of the saddle members with the iiywheel face.

With continued reference to Vthe drawings, wherein like reference characters designate like parts throughoutthe' several figures thereof, the clutch housing is designated generally at I and is adapted to b e'bolted to the engine bell housing in well known-manner. Secured to :flange 4`, o f engine ordrivingI shaft 5, by means of bolts 6 or the like, is web portion 'l of iiywheel 8. The periphery of flywheel 8 is"`provided with the usual starting gear 9. f

Disposed in axial alignment with the driving shaft, and mounted for rotation, is driven shaft Il, which is reduced at I2 and journaled'in a suitable antifriction pilot bearing assembly I3, secured in a bore in the end of shaft 5, which is y lubricated in a manner presently to be described. Driven shaft II is adapted to have the other end thereof operably connected to a suitable gear changing or other variable speed transmission (not shown) for applying the torque applied to the final driven member. Driven shaft II has a splined portion I4, on which a correspondingly splined hub I5 is slidably mounted. Hub I5 is resiliently connected to driven disk I1 by means of a dampener mechanism that will presently be described. Disk I1 is providedy with a plurality of radially extending slots I8,. which extend to the periphery thereof andl terminate at their inner ends in openings I 8. Slots I8 give disk I1 4extreme flexibility in an axial direction and permit accommodation thereof to slight angular misalignment of the clutchplates, While apertures I8 provide for distribution of cooling air on each side of disk I1 as will be more particularly hereinafter pointed out.

Each face of disk I1 near the periphery thereof is provided wlth a lining I9 and 2,0 respectively, which may consist of any material that has the required characteristics to give the correct frictional gripping force, and at the Sametime has wearing qualities adapting it for this purpose. Frictional facings .I9 vand 20 may be secured to disk I1 in any suitable manner, vas for instance by rivets or the like.

Referring more particularly to Figure 3 of the drawings, hub I5 is provided centrally of its lengthwith a ange 22 which is slotted at intervals around its periphery to provide substantially rectangular recesses having walls 23 which constitute driving faces. Walls 23, near the outer periphery offlange 22, are given a slightly curved coniiguration for a purpose that will presently 4 appear. -The recesses formed in flange 22 are shown in the present instance as being six in number, and while this number has been found to give very good results in practice, it is understood that the recesses may be more or less than six in number Without sacrificing the advantages of the present invention. Flange 22 rather snugly ts in an aperture 24 formed in plate I1 forrV limited angular movement with respect thereto. Substantially rectangularl notches 25 having walls 26 providing driving faces are formed in disk I1 and are coextensive with those .formed in an'ge 22. 'Ihe inner ends of walls 25 of notches 25 formed in plate I1 are given a diverging conguration for a purpose that will presently appear.

Disk I1 is resiliently connected to hub I5 for yieldingly transmitting torque thereto by means l consisting of a plurality of leaf spring units or packs r21, which are disposed rather snugly at one end-in recesses 23 formed in flange 22, and at the other end seat rather closely in vrecesses 25 formed.in disk I1. Y i

From the structure so, far developed, it will be seen that should a sudden rotational impulse be given disk I1 in clockwise or counterclockwise direction, hub I5 will not immediately respond thereto, but springs 21 will flex and take a position in surface contact with walls 23 and A25. It is therefore seen that springs 21 establish aresilient yielding connection between disk I1 andk hub I5, thus effectively n from one member to the other.v Itf will m reover be'seenthat the'resilient coupling iis double acting, and if 'a vehicle provided with this mechanism is proceeding .down grade with the transmission in high gear, and-with the clutch thrown out, if the operator suddenly reengages the clutch, hub I5 becomes the driving member, and the sudden rotational impulse transmitted by member I5 to member I1 is cushioned by springs 21. Ii' the resilient connection disclosed werefnot interposed between hub I5 and disk I1, a severe shock would be transmitted from hub I5 to disk I 1 upon reengagement of the clutch with possible damage to the driving mechanism. However, with the present resilient connection incorporated in the mechanism,. upon reengagement of the clutch, springs 21 will merely ex in the opposite direction, cushioning any torque impulse that might result in a damaging shock to the mechanism. Springs 21 are preferably designed and tempered so as to present such a degree of stiifness during normal torque delivering operation that they will not flex to their vfullest extent or into full contact with the curved faces dening notches 23 and 25, but will only be slightly flexed so that each impulse of torque delivered by the engine can be absorbed .and stored in the spring thereby giving a smooth torque delivery to the final driven member.

Leaf springs 21 may be flexed so as to lie over the full area of the curved faces of recesses -23 and 25, in response'to-a reasonably large sudden impulse transmitting eifort from one member to the other. To prevent undue flexing of springs 21, under extremely severe conditions, disposed on either side of disk I1 and rigidly secured theretoby means of rivets 28 or the like, are a pair of plates 29; Plates 29 are offset at 3| to provide a sliding ltbetween the same and iiange 22 formed on hub l5, Plates-.29 are further provided with recesses 32, which are coextensive with recesses 25 formed in disk I1 inwardly to the periphery of disk I1, where' the walls thereof diverge as shown in Figure 3 of the drawings.

The clearance provided between the springs 21 and the diverging walls of plate 29 is suflicient to allow normal flexing movement of springs 21 under fairly severe conditions, and it will ,be noted that the outer portions of the walls dening recesses 32 in plates 29 are ush with the recesses 25 formed in plate I1, and therefore form additional driving faces, and the inner extremities of recesses 32 form stops so that when springs 21 have been flexed to a predetermined normal extent, the outer leaves of springs 21 contact vtivexdrive thereafter is established between disk I1 and hub I5. It is to be understood that springs 21 are designed to absorb any reasonably large torque impulse without iiexing suificiently to contact `with vthe diverging faces of recesses 32.

vThus the limiting walls of recesses 32 are seen to constitute a safety device to prevent springs 21 from being flexed beyond their elastic limit, which might cause them to take a permanent set or to be excessively distorted.

A slidable connection is provided between the inner periphery of plate 29 and flange 22 to permit their relative movement during flexing of springs 21, by means of shouldered pins 33 whichv extend through oversized openings 34 formed in plates 29. Pins 33 are inserted in openings 34,

vand a plate 35 is disposed on opposite sides thereof and through which the end portions of pins 33 extend. After assembly, the ends of pins 33 are then headed over as shown in Flgure 1, so that plates 35'are rigidly connected to each other and permit a limited range of movement of disk I1 on flange 22 of hub I5. It will be also noted,

by referring to Figure of the drawings, that degree of rigidity which thereby prevents dis-' tortion and warpage thereof during clutch operation. Plate 4| is driven by flywheel 8, and is per- Amitted to move axially thereof forclutching and declutching purposes by means of pairs of ears or lugs 42 that are provided on plate 4I at approximately 120 intervals, and are preferably formed integral therewith. Lugs 42 extend outwardly beyond the periphery of plate 4I into saddle members 43 which provide driving faces 44`that closely abut the opposite side of each lug assembly, and are adapted for sliding engagement therewith. Saddle members 43 are .provided with a space indicated at 45 (Figure 5) that is suiiicient to accommodate lugs 42 throughout their entire range of sliding clutching and declutching movements. The lower ends of saddle members 43 are deiiected to lie in a horizontal plane and are apertured and secured to the fiat face of plates 46 by means of cap screws 41 or the like. Removably disposed between plates 46 and the face of the ywheel are a plurality of shims 46 which may be inserted or removed for the purpose of adjusting plate 46 toward and away from the iiywheel face. Shims 48 are slottedso that one or more of them may be removed from the assembly Without disturbing the saddle members or plates 46 by merely loosening bolts 41, removing cap screws 49, and slidably manipulating the shims.

. Saddle members 43l are preferably formed of sheet metal stampings because their novel design renders this material entirely suitable for this purpose. It is therefore seen that driving plate 4| is mounted for rotation with flywheel 8 -in a very economical manner, and is at the same time permitted to move axially thereof throughout a limited range of movement. Each plate 46 is held in place on the flywheel by means of a cap screw 49 so that screws 41, along with saddle 43 may be removed without disturbing. plate 46 and the set of shims 48 associated therewith. Each shim 48 is provided with small apertures 50 into which a suitable tool may be inserted for the puipose of withdrawing the shims.

Plate 4| is normally urged toward the iiywheel by means of a spring assembly consisting of a plurality of springs interposed betweeny a pair of annular reacting members. Plate 4| is provided with an' annular seat 5| against which an annu- ,lar reacting plate 52, having a flange 53, is adapted to rest. Plate 52 receives the reaction of springs 55 and transmits it to plate 4|, and is 35 made of sheet metal suitably formed to giveit sumcient rigidity. 'Plate 52 is provided at suitable intervals around-"its .periphery with -depressed portions `54 which are adapted to center and form seats for one end of compression springs 55. Interposed between springs 55 and'plate 52 are heat insulating gaskets 56 which may consist of any suitablematerial having heat insulating properties, for preventing the transfer of heat from pressure plate 4| to springs 55-so that their proper temper may be maintained.

The other ends of springs 55 cooperate with an annular plate 51 which is provided with depressions 58 for centering the springs. Springs 55 seat directly against plate 51 for the reason that no heat is generated by any of the elements in contact with'plate 51 and hence no insulating means are required. Plate 51 is provided at approximately intervals .about its periphery with offset portions 59 which receive the inner ends of throwout levers 6 I, and which are suitably reenforced in these regions by suitable forming operations.

and which terminates in 'an annular flange 62 which is normal to the clutch axis. Seating on flange 62 and preferably secured thereto as by welding or the like is a relatively thick hard metal ring 63. Ring 63, in response to the action of springs 55, is urged toward and rests against curved faces 64 formed on throwout levers 6|. In view of the fact that levers 6| are three in number, the action thereof would produce localized pressures in ange 62, if it contacted them directly. Therefore, ring 63 being of substantial thickness and rigidity, distributes the reaction pressure of throwout levers 6| around the entire periphery of ange 62 which is of relatively light gauge sheet metal.

While the spring organization just described gives excellent results and is preferred, springs 55 and seat members 52 and 51 could be replaced by a singleA spring of the type disclosed in the application of Charles B. Spase, Serial No. 527,429,'filed April 3, l1931, and good results obtained.

The inner edge of plate 51 is prol vided with a flange extending toward the flywheel Throwout levers are preferably three in numthree Vpoint support, and accordingly exerts an equal pressure upon each lever. The outer end of each throwout lever 6| is disposed between a pair of 'lugs 42 and is journaled therein on a pin 66 seating in apertures in lugs 42. In view of thefact that pins 66 abut walls 44 of saddle members 43, no other means than this is required to hold them in assembled position in the mechanism. Provided on opposite faces of levers 6| are curved fulcrum faces 61 and 68 respectively. Fulcrum face 61 cooperates with the outer face of plate 4 6 when declutching `operations are being effected, and fulcrum face 69 cooperates With a hardened steel plug or bearing member 69, that is frictionally fitted in an aperture 1| formed in the top of each saddle member 43. Enough clearance is provided between plates 46 and plugs 69 to permit levers 6| to rock freely therebetween.

sure exerted thereon by fulcrums 68, and at the same time present a surface for cooperation with fulcrums 68 that has good wearing qualities.

It should be noted that there is no tendency whatever for levers 6| to rotate in a' plane normal to the clutch axis in response to rotation of the clutch mechanism, becausel they are disposed exactly radially, and have each end of their pivots supported in lugs 42, so no tendency to bind is present.

From the structure so far developed, it will be seen that plate 4| is urged toward the flywheel by the direc/it pressure of thek inner ends of springs 55 and plate4l is further urged 'toward the iiywheel by the other ends of springs 55 which bear against levers 6|.and exert an amplified force upon plate 4|, due to Atheir force multiplying disposition. When the inner ends of levers 6| are urged toward the flywheel, fulcrum faces 61 thereof will contact with the top of plates 46, thus urging pivots 466 away from the flywheel, and

on levers 6| are held in tight contact with plugs 69 by virtue of the pressure exerted on levers 6I 10 by springs 55, thus urging plate 4Iv toward the flywheel web. f

Formed on the topface of lugs 42 are aper-l tured ears 18 through which a pin may be inserted to hold throwout levers 6| in assembled relationship with the rest of the mechanism while assembly and disassembly operations are being carried out. i

"I'he mechanism for causing declutching movements of throwout levers 6| will now be described. 20 Cooperating with curved faces 8| formed on the inner extremities of levers 6I is the flat face of ball race 82 which cooperates with antifriction balls 83 disposed therebetween and a similar ball race 84. Ball races 82 and 84 are held in loosely assembled relation with respect to each other by means of retainer member 85. Ball race 84 is rigidly mounted upon a sleeve 86, having an offset portion 81, that is slidably mounted upon a supporting sleeve 88, having an offset portion 89 upon which offset portion 81 of sleeve 86 is slidably associated. Supporting sleeve 88 is preferably formed integrally with housing I, and has the bearing faces thereof machined and ground-so as to be in -exact alignment with shaft 5 when the clutch is assembled, and to provide a close flt with sleeve .86, for sliding movement with respect thereto. Supporting sleeve 88 is spaced considerably from driven shaft I and is accordingly independent thereof.

Driven shaft I I is provided with a central\bore 9| which extends entirely through reduced portion I2 thereof in one direction, and the other end communicates with a transverse bore 92, into which is tapped a suitable grease tting 93. 'I'he annular portion of support 88 provides an annular space 94 in which grease fitting 93 is adapted to travel in a circular path with shaftI I. Membjers 81 and 89 are cut away, preferably vat the top thereof, suiciently at 95 and 96 respectively to allow the introduction of a grease gun for cooperation with grease fitting 93 to introduce lubricant into passages 9| and 92. When it is desired to -lubricate vbearing I3, the grease gun is inserted through the usual opening in housing I and shaft I| rotated in any suitable mannerv to bring grease fitting 93 into coincidence with apertures 95 and 96 for connection with grease fitting 93. The grease or other suitable lubricantis' forced into passages 9| and 92 and thence into y the antifriction bearing assembly I3 located in the flywheel web. y

Lubrication for the sliding movements of sleeve 86 upon supporting sleeve 88 is provided by a grease fitting 91 which is tapped into passage 98 communicating with a lubricant .distributing groove 99 located in sleeve 86. Access to this grease fitting is also gained through the usual hand hole located in the clutch housing. Formed on opposite sides of sleeve 86 are lugs ||J| which cooperate with throwout fingers |02 connected by yoke |03. Rigidly secured in yoke |03 are shafts |04 and |05 which arejournaled in` `the clutch housing in well known manner (not shown).

Mounted on the end of shaft |04 is the usual clutch pedalinot shown) While sleeve 86 l may be keyed or splined to supporting'sleeve 88 in any desirable manner to prevent rotation thereof, and at the same time permit axial movement for clutching and declutching purposes, I prefer to provide an apertured ear or lug member |06 5 upon sleeve 86 forY cooperation with lug |01 secured in the clutch housing.

It will be particularlyinotedthat driven shaft ts loosely in supporting sleeve 88 which is stationarily. mounted in the housing, and there- 10 fore substantial eccentricity or angularity of misalignment of driving shaft 5 and driven shaft II can have no substantial effect upon the operation of the throwout bearing assembly. Moreover, since there is slight possibility of driving shaft l5 5 being thrown out of alignment, and the bearing faces of support 88 are carefullyv machined to lie exactly parallel to driving shaft 5, a permanent alignment is assured7 and the throwout bearing assembly will always cause plate 4| to be parallel 20 to the flywheel regardless of whether the clutch is engaged or disengaged. Moreover due to the three point engagement `of member 63 therewith levers 6| will be held tight at all times regardless of manufacturing inaccuracies or inaccuracies 25 that arise due to wear by the engagement of collar 63 with the levers. During clutching and declutching operations the ends oflevers 6| will also have a three point support on the face of the throwout bearing assembly, while the throwout 20 bearing is positively maintained in proper alignment by virtue of the stationary guiding means formed on the clutch housing, providing smooth clutch action with minimum pedal operation at all times. 35

Moreover, it will be noted that due to the entire absence of a rim on the flywheel, and of the usual cover or any other structure associatedv with the clutch mechanism that might impede air flow inluced by rotation of the clutch elements, or 40 inhibit free radiation of heat'therefrom, and also the plane face of the flywheel beyond the driving ,face thereof, dissipation of heat from the clutch elements by radiation and convection is extremely rapid. -'Moreover, as the facing material wears 45 and particles .thereof are dislodged, this material is free to leave the 4clutch mechanism and is carried away by the air stream produced by rotation of the clutch elements. The absence of the usual rim on the flywheel moreover ma- 50 terially reduces machining and production costs and adapts it for large volume, low cost production methods.

In view of the fact that reaction' plugs 69 and plate 46 may be adjusted toward and away from 55 the flywheel by means of shims 48 interposed therebetween, should it be found upon assembling clutch mechanism at the factory that'plate 4I is disposed in non-parallel relation with the'ily-N wheel web, shims '48 may be inserted or with- 60 drawn from certain saddle members 43 in order -to bring about parallel relation/of the plates.

Ashas just been pointed out, each' plate 46 is held in place on flywheel 8 by means of a single bolt 49, which is independent of saddle member 43, 65 therefore saddle 'members 43 may be removed from the clutch mechanism without in any way disturbing shims 48 and the proper adjustment will thereby be maintained.' It is contemplated that this adjustment be in the nature of an initial 70 factory. adjustment for the reason that after the' clutch mechanism has been in use, there is no chance for plate 4| to Work itself intq non-parallel relation' with the flywheel web because the wear on the faces of levers 6| occurs to an equal extent 75 upon each of them, since they are acted upon by an equal force, namely one-third of the total pressure exerted by springs 55, due tothe nature of the lconnection existing betweenv the springs 55 and collar 63.

Air currents induced by the rotation of the clutch elements are drawn into louvers H0 provided in the cover III for the hand opening in the housing, and are` caused to ilow outwardly l0 over the faces of the plate, thereby abstracting heat therefrom and at the same time carrying away any particles that have been dislodged from the facing material as a result of operation. The openings I8 formed in disc I1 permit air to enter and flow over the face thereof adjacent the flywheel. The continuous outward flow' of air over both faces of disc l1 effectively cools all'of the clutch elements, and at the same time prevents the conduction of heat inwardly into the dampener assembly thereby avoiding the possibility of drawing or seriously modifying the temper of leaf springs 21 thereof.

It will therefore be seen that low cost, highly effective, simplified clutch mechanism has been 25 provided in which slight inaccuracies in machining, assembly, or due to wear in use have no substantial effect and which, due to its heat dissipating capabilities, thorough ventilation and selfaligning qualities of its parts will, at moderate pedal pressures, handle substantially greater loads with materially longer life than prior clutch mechanisms of like size.

The invention may be embodied in other specie forms without departing from the spirit or 35.essential `characteristics thereof. The present embodiment is therefore to be considered in. all i respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of-equivalency 'ofgthe claims are therefore intended to be embraced therein. p

W'hat is claimed and desired to be secured by United States Letters Patent is:

l. In a clutch mechanism, av driving member;

a driving clutch plate; spring means urging said driving clutch plate into engaged position; lever means' for withdrawing said driving clutch plate into disengaged position against the action of said spring means; and'means for fulcruming said lever means upon 'said driving member comprising a plurality of apertured members having fulcruming faces, secured to said driving member and through which said lever means extends, means associated -with said apertured members for permitting adjustment thereof toward and away vfrom said driving member whereby substantial parallelism of said driving member and '60 said driving clutch plate may be established, and

means associated with said apertured members whereby said adjustment may be effected without removing said apertured members fromvthe mechanism. v y

2. In a clutch mechanism, a driving member;

a driving clutch plate; spring means urging said driving clutch plate into engaged position; lever means for withdrawing said driving clutch plate into disengaged position against the action of said spring means; means fulcruming said lever means upon said driving member comprising a plurality of apertured members having fulcruming faces and secured to said driving member and into which said lever means extends; means for adjustingsaid apertured members toward. and

away from said driving member, whereby substantial parallelism of said driving member and said driving clutch plate may` be established; and means associated with said driving member whereby said apertured members can be removed 5 from said mechanism without disturbing said adjusting means."

3. In a clutch, in sub-combination, a rotatable clutch member, a plurality of outwardly extending levers supported by said member; a' pressed 10 metal plate element having a surface disposed normal to the axis of rotation; a plurality of springs seating against said plate element and urging the latter axially toward said levers; and

a comparatively rigid,y flat annular member se- 15` cured to said plate element in contact with the normal surface thereof; for preventing distortion of said plate element under the action of said springs and levers.

4. In a clutch in sub-combination, a flywheel 20 Y having a surface disposed normal to the axis off rotation, a U -shaped member and a plate member secured to the surface of said flywheel and constituting a saddle assembly, said plate member being disposed between said flywheel and the legs 25 of said U-shaped member, thereby defining a substantially rectangular aperture, and a plurality of shims detachably disposed between said plate and said flywheel, whereby said saddle assembly may be adjusted toward and away from 30 the latter.

5. vIna clutch, in sub-combination, a rotatable supporting structure, an annular clutch plate mounted upon said supporting structure for synchronous rotation therewith and for movement 35 axially thereof, said clutch plate having a frici tional driving surface disposed substantially normal to the axis of rotation, the inner cylindrical wall of said clutch plate having an abutment face provided thereon facing away from said sup- 40 porting structure, an annular force distributing member disposed within said clutch plate and having its surface substantially flush with the frictional surface of said clutch plate, and having an offset flange engaging'behind said abutment face, 45 and a plurality of springs seating upon said force distributing member and urgingpthe latter into engagement with said clutch plate.

6. In a clutch, in sub-combination, a saddle assembly for fulcruming a clutch lever, compris- 50 ing a generally U-shaped bracket, a fulcrum plate adapted to be secured to said bracket and bridge the legs thereof, and a fulcrum plug having a reduced portion seating in the bight' of said bracket, the surfaces of said fulcrumplate and 55 fulcrum plug being substantially parallel and deflning a. Ipair of fulcrum faces for a declutching lever.

7. In a clutch, driving and driven'members mounted for engagement and disengagement, a e0 plurality 'of outwardly extendinglevers for controlling engagementand disengagement of said members, a plate element having an annular surface disposed normal tothe axis of the clutch and engaging the inner ends of said levers, a e5 plurality of compression springs seating against, and urging said plate element axially toward said levers;` and a throwout'mechanism mounted for axial movement, said throwout mechanism supporting a bearing having an annular surface nor- 70 mal to the clutch axis and co-extensive with the surface of said plate element, the inner ends of ment against which said springs seat being axially offset va substantial distange from the said annular surface of, said -plate element.`

8. In a clutch, driving and driven members mounted for engagement and disengagement; a plurality of outwardly extending levers for controlling engagement and disengagement of said members; a'plate element having an annular surface disposed normal to the axis ofthe clutch and engaging the inner ends oi said levers, a.

plurality of compression springs seating against,

and urging said plate element axially toward said levers; a throwout mechanism mounted for axial movement, said throwout mechanism supporting 9. In a clutch, driving and driven members mounted for engagement and disengagement; a plurality of outwardly extending levers forV controlling engagement and disengagement of said members; a plate element having an annular.

surface disposed normal to the axis of the clutch and engaging the inner ends of said levers, al plurality of compression springs seating against, and urging said plate element axially toward said levers; a throwout mechanism mounted for axial movement, said throwout mechanism supporting a bearing having an annularsurface normal to the clutch axis and co-extensive with the surface of said plate element, the inner ends of said levers being disposed, and adapted to be clamped between said plate element and said bearing surfaces, said plate element being provided with a cup-shaped portion Within which'said bearing nests, said bearing being spaced from said plate element at all points, said annular surface de. r20

lining the bottom of the'cup.

ROBERT P. Lim/'1a.V 

